A 38th minute send off for uncompromising Canberra Cosmos defender David Milin scuttled the visitors' chances of a repeat of last season's upset performance against Marconi when the teams met in Sydney on Saturday night.
A rash challenge on the edge of the box by Milin on the slippery Marconi customer Chad Gibson brought an instant flash of red from referee Brad Hugo who was right on the spot to adjudicate.
It looked a bad challenge, but not really a clear-cut professional foul and many would have considered the punishment worthy of just a caution.
Playing for almost the last hour with ten men Canberra worked hard and kept their shape well, always staying in contention of getting at least a point, but in the end being unable to recover from conceding a 53rd minute goal to Marconi newcomer Angelo Costanzo.
Marconi did most of the attacking in the game, but it often broke down inside the area, without the Canberra defenders resorting to anything as drastic as Milin's reckless challenge.
A flying header from Darren McDonald in the 9th minute gave the Cosmos their first scare when the big blond midfielder rose high to meet one of many Brendan Renaud crosses from the left, but the ball struck the outside of the post with keeper Barney Smith seemingly in real trouble.
Andy Ravanello seized on a stray pass to offer Canberra's only solid first half chance when his firm shot from an angle was palmed away by David Aceski in the 31st.
Marconi went close with efforts from Simon Bell, Norman Tome and Chad Gibson, all of whom had shots which were blocked by defenders.
Tome had the ball in the net in the first few minutes after the break, but assistant referee Rod Allen had his flag up long before the ball reached the target after Gibson had provided the final probing pass.
Costanzo made a great run from deep in the 53rd and fed Tome, who in turn found Gibson wide on the right. The tricky wide player turned the ball back into the centre where Costanzo, who had continued his run into the box, bundled the ball over the line with ease for the only goal of the game.
John Maisano then clipped a shot over the bar while Tome and Raphael Bove missed other chances before Brad Scott fired wide for the visitors in the 61st as Jon Angelucci and Alex Castro attempted to bring their side back into the game, with some useful combinations.
Marconi could have made it 2-0 in stoppage time when Maisono was upended in the box by Toplica Popovich, but the wronged striker sent his spot kick crashing against the angle of the bar, meaning that the home side had to settle for the narrow 1-0 win.
For Marconi McDonald was always busy and contributed throughout, Gibson and Renaud were always involved and both Maisano and Bove did their jobs well. Simon Bell was an interesting inclusion and came through with flying colours as a central attacking player.
Robbie Hooker was solid at the back for Canberra who had Angelucci toiling well up front and the evergreen Ravanello was creative for much of the game.
Marconi played some good football while Canberra remained competitive on a very pleasant evening where the crowd for the season opener was down a few hundred on the corresponding fixture last term.
The jury may therefore be out on whether the switch back to Saturday nights is going to be a sound move by the Marconi club who played most of their matches last season on a Sunday and at an hour earlier starting time than this 7 pm kick off.